| Alaster McDonnell | |
| Full Name: | Alaster Colla McDonnell |
| Birth Date: | 20 January 1867 |
| Birth Place: | Dublin, Ireland |
| Death Place: | Richmond, Surrey, England |
| Position: | Halfback |
| Repyears1: | 1889–91 |
| Repcaps1: | 4 |
| Reppoints1: | 0 |
Alaster Colla McDonnell (20 January 1867 – 15 October 1950) was an Irish international rugby union player.
The eldest son of a barrister, McDonnell was born in Dublin and educated at The Royal School, Armagh, before undertaking further studies at Trinity College Dublin, where he played varsity rugby. He gained four caps as a halfback for Ireland, making his debut in a win over Wales at Swansea in 1889.[1]
McDonnell returned to Royal School Armagh as headmaster in 1897, remaining in the role until 1904. He was later an assistant master at Eton College and also served as a county magistrate in Mortlake, London.[2] [3]